Migrate validate_json.py script to rust in run-make/rustdoc-map-file test

Cargo.lock

@@ -3149,6 +3149,7 @@ dependencies = [
  "gimli 0.31.0",
  "object 0.36.2",
  "regex",
+ "serde_json",
  "similar",
  "wasmparser 0.214.0",
 ]

src/tools/run-make-support/Cargo.toml

@@ -11,3 +11,4 @@ wasmparser = { version = "0.214", default-features = false, features = ["std"] }
 regex = "1.8" # 1.8 to avoid memchr 2.6.0, as 2.5.0 is pinned in the workspace
 gimli = "0.31.0"
 build_helper = { path = "../build_helper" }
+serde_json = "1.0"

src/tools/run-make-support/src/lib.rs

@@ -38,6 +38,7 @@ pub use bstr;
 pub use gimli;
 pub use object;
 pub use regex;
+pub use serde_json;
 pub use wasmparser;
 
 // Re-exports of external dependencies.

tests/run-make/rustdoc-map-file/rmake.rs

@@ -1,13 +1,54 @@
-use run_make_support::{python_command, rustdoc};
+// This test ensures that all items from `foo` are correctly generated into the `redirect-map.json`
+// file with `--generate-redirect-map` rustdoc option.
+
+use std::path::Path;
+
+use run_make_support::rfs::read_to_string;
+use run_make_support::{path, rustdoc, serde_json};
 
 fn main() {
     let out_dir = "out";
+    let crate_name = "foo";
     rustdoc()
         .input("foo.rs")
+        .crate_name(crate_name)
         .arg("-Zunstable-options")
         .arg("--generate-redirect-map")
         .out_dir(&out_dir)
         .run();
-    // FIXME (GuillaumeGomez): Port the python script to Rust as well.
-    python_command().arg("validate_json.py").arg(&out_dir).run();
+
+    let generated = read_to_string(path(out_dir).join(crate_name).join("redirect-map.json"));
+    let expected = read_to_string("expected.json");
+    let generated: serde_json::Value =
+        serde_json::from_str(&generated).expect("failed to parse JSON");
+    let expected: serde_json::Value =
+        serde_json::from_str(&expected).expect("failed to parse JSON");
+    let expected = expected.as_object().unwrap();
+
+    let mut differences = Vec::new();
+    for (key, expected_value) in expected.iter() {
+        match generated.get(key) {
+            Some(value) => {
+                if expected_value != value {
+                    differences.push(format!(
+                        "values for key `{key}` don't match: `{expected_value:?}` != `{value:?}`"
+                    ));
+                }
+            }
+            None => differences.push(format!("missing key `{key}`")),
+        }
+    }
+    for (key, data) in generated.as_object().unwrap().iter() {
+        if !expected.contains_key(key) {
+            differences.push(format!("Extra data not expected: key: `{key}`, data: `{data}`"));
+        }
+    }
+
+    if !differences.is_empty() {
+        eprintln!("Found differences in JSON files:");
+        for diff in differences {
+            eprintln!("=> {diff}");
+        }
+        panic!("Found differences in JSON files");
+    }
 }